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Electrical engineer Chris Gammell has spent almost a year creating his new online electronics program called “Contextual Electronics“, and we’re excited to share this with our readers. You may have heard of Chris from his regular successful podcast with Dave Jones  – “The Amp Hour“.

Chris has the knowledge and expertise to take electronic ideas from simply that – an idea, right through to production. And by participating in his Contextual Electronics program you can learn the required skills to do this as well. Chris gives us a quick introduction in this video.

Contextual Electronics is a new program aimed at electronics enthusiasts who are ready to take their Arduino (or similar platform) skills to the next level. The first session of the course is an 8 week program that will teach you how to design a large, multi-function Arduino shield using KiCad, the open source CAD software.

It will also show you all of the design decisions that go into making the project. Here are some of the sub-circuits included in the 4-layer PCB design:

• High level signals measurement using op-amps

• Power supply output

• Relay control

• LED driver circuitry

• Current source output

The course has a large community component, so you will be grouped with others learning at the same time, regardless of where you’re located in the world. The goal of the course and the community aspect is to make you more confident designing a project so you can go and design your own.

Future sessions of the course will also go over building, troubleshooting and coding for the shield described above. There is also a free short course that you can review to give you an idea of Chris’ methods and what the Contextual Electronics program will be like.

Additional courses will be developed using other popular development boards, including the Raspberry Pi and BeagleBone. For a more in-depth introduction, check out this video.

Frankly the program will help all of you who are ready to take your ideas and projects off the breadboard and into finished products, and with the guidance available with the program and the use of open-source tools you’ll be up and making things you can be proud of showing to friends or even potential employers. For more information about the program, and to sign up – visit the Contextual Electronics program website.

And if you enjoyed this article, or want to introduce someone else to the interesting world of Arduino – check out my book (now in a third printing!) “Arduino Workshop”.

The post Learn electronics with Chris Gammell and “Contextual Electronics” appeared first on tronixstuff.

Introduction

Slowly we’re working through the stock of old kits, and in this article we have the “Fluorescent Lamp” simulator from Talking Electronics. To save repeating myself you can read more about Talking Electronics here and watch interviews of the founder Colin Mitchell here.

So why would you want to simulate a fluoro’ tube anyway? Model railways! When your model world moves from day to night, it’s neat to have street lights and so on “flicker” on just like the real thing. And thus you can create this effect as well. It can drive incandescent lamps up to 12V, and allowing it to be powered easily from most layouts.

The kit was originally described in the Talking Electronics book “Electronics for Model Railways” (volume 1) which was full of useful and interesting electronics to liven up any layout. The book may now out of print however at the time of writing this you can download or view most of the projects from the index column of the Talking Electronics website… or contact Talking Electronics if they have any copies of the book (or kit) to sell.

Assembly

Time was not kind to the kit, to be frank it was surprising to find one at all:

(Just a note for any over-enthusiastic readers, Talking Electronics is no longer at the address on the bag shown above). However it was complete and ready for assembly. The PCB has a silk-screen with the required component placement information, polarities and so on – a first for the time:

The instructions and “how it works” are not included with the kit as you were meant to have the book, however TE have made them available as a separate download (.pdf) . The kit included everything required to get started, and there’s an LED which replicates the effect so you can test the board without having to watch the connected bulb (which may be a distance away). Finally an IC socket is included

The actual assembly process was very straight forward, which simply required starting with the low-profile components and working up to the large ones:

The only problem with the PCB was the holes – looks like only one drill size had been used (apart from the mounting holes) which made getting that rectifier diode in a little tricky. Otherwise it was smooth sailing.

Not having a model railway at the moment left me with the simple example of the onboard LED and a small incandescent globe to try with the circuit. You can see the kit working in this video.

John – Why do you publish these “Old Kit Reviews”?

They’re more of  a selfish article, like many electronics enthusiasts I have enjoyed kits for decades – and finding kits from days gone by is a treat. From various feedback some of you are enjoying them, so they will continue for fun and some nostalgia. If you’re not interested, just ignore the posts starting with “Old”!

Conclusion

For a kit from the mid-1980s, this would have solved the problem neatly for model railway enthusiasts. By using two or more of the kits with different capacitor values, many model lights could blink on with seemingly random patterns. However it’s 2014 so you could use a PIC10F200 or ATtiny45 and reduce the board space and increase the blinking potential.

Nevertheless, it was an interesting example of what’s possible with a digital logic IC. Full-sized images and a lot more information about the kit are available on flickr. And if you enjoyed this article, or want to introduce someone else to the interesting world of Arduino – check out my book (now in a third printing!) “Arduino Workshop”.

The post Old Kit Review – Talking Electronics Fluorescent Simulator appeared first on tronixstuff.

Introduction

This is the second of three articles that will examine the LM391x series of LED driver ICs. The first covered the LM3914, this will cover the LM3915 and the LM3916 will follow. The goal of these is to have you using the parts in a small amount of time and experiment with your driver ICs, from which point you can research further into their theory and application.

Although these parts have been around for many years, the LM3915 isn’t used that much however for the sake of completeness we’re writing the tutorial. The LM3915 offers a simple way to display a logarithmic voltage level using one or more groups of ten LEDs with a minimum of fuss. If you’re wanting to make a VU meter, you should use the LM3916 which we will cover in the final instalment of this trilogy.

Instead of having each LED represent a voltage level as with the LM3914, each LED connected to the LM3915 represents a 3 dB (decibel) change in the power level of the signal. For more on decibels, check out Wikipedia.

To display these power level changes we’ll run through a couple of examples that you can use in your own projects and hopefully give you some ideas for the future. Originally by National Semiconductor, the LM391X series is now handled by Texas Instruments.

Getting Started

You will need the LM3915 data sheet, so please download that and keep it as a reference. First – back to basics. The LM3915 controls ten LEDs. It controls the current through the LEDs with the use of only one resistor, and the LEDs can appear in a bar graph or single ‘dot’ when in use. The LM3915 contains a ten-stage voltage divider, each stage when reached will illuminate the matching LED (and those below it in level meter mode).

Let’s consider the most basic of examples (from page two of the data sheet) – a simple logarithmic display of voltage between 0 and 10V:

After building the circuit you can connect a signal to measure via pin 5, and the GND to pin 2. We’ve built the circuit exactly as above on some stripboard for demonstration purposes, with the only difference being the use of an 8.2kΩ resistor for R2:

To show this in action we use a signal of varying AC voltage – a sine wave at around 2 kHz. In the following video, you can see the comparison of the signal’s voltage against the LEDs being illuminated, and you will see the logarithmic voltage increase represented by the LEDs:

We used the bar display mode for the voltage increase, and the dot display mode for the voltage decrease. Did you notice that during the voltage decrease, the LEDs below the maximum level being displayed were dim? As the signal’s voltage was varying very quickly, the change in the LED’s location is a blur due to the speed of change. In the video below, we’ve slowed the frequency right down but kept the same maximum voltage.

Well that was a lot of fun, and gives you an idea of what is possible with the LM3915.

Displaying weaker signals

In non-theoretical situations your input signal won’t conveniently be between 0 and 10 V. For example the line level on audio equipment can vary between 1 and 3V peak to peak. For example, here’s a random DSO image from measuring the headphone output on my computer whilst playing some typical music:

Although it’s an AC signal we’ll treat it as DC for simplicity. So to display this random low DC voltage signal we’ll reduce the range of the display to 0~3V DC. This is done using  the same method as with the LM3914 – with maths and different resistors.

Consider the following formulae:

As you can see the LED current (Iled) is simple, however we’ll need to solve for R1 and R2 with the first formula to get our required Vref of 3V. For our example circuit I use 2.2kΩ for R2 which gives a value of 1.8kΩ for R1. However putting those values in the ILED formula gives a pretty low current for the LEDs, about 8.3 mA. Live and learn – so spend time experimenting with values so you can match the required Vref and ILED.

Nevertheless in this video below we have the Vref of 3V and some music in from the computer as a sample source of low-voltage DC. This is not a VU meter! Wait for the LM3916 article to do that.

Again due to the rapid rate of change of the voltage, there is the blue between the maximum level at the time and 0V.

Chaining multiple LM3915s

This is covered well in the data sheet, so read it for more on using two LM3915s. Plus there are some great example circuits in the data sheet, for example the 100W audio power meter on page 26 and the vibration meter (using a piezo) on page 18.

Conclusion

As always I hope you found this useful. Don’t forget to stay tuned for the final instalment about the LM3916. And if you made it this far – check out my new book “Arduino Workshop” from No Starch Press.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitter, Google+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Introduction

This is the second of three articles that will examine the LM391x series of LED driver ICs. The first covered the LM3914, this will cover the LM3915 and the LM3916 will follow. The goal of these is to have you using the parts in a small amount of time and experiment with your driver ICs, from which point you can research further into their theory and application.

Although these parts have been around for many years, the LM3915 isn’t used that much however for the sake of completeness we’re writing the tutorial. The LM3915 offers a simple way to display a logarithmic voltage level using one or more groups of ten LEDs with a minimum of fuss. If you’re wanting to make a VU meter, you should use the LM3916 which we will cover in the final instalment of this trilogy.

Instead of having each LED represent a voltage level as with the LM3914, each LED connected to the LM3915 represents a 3 dB (decibel) change in the power level of the signal. For more on decibels, check out Wikipedia.

To display these power level changes we’ll run through a couple of examples that you can use in your own projects and hopefully give you some ideas for the future. Originally by National Semiconductor, the LM391X series is now handled by Texas Instruments.

Getting Started

You will need the LM3915 data sheet, so please download that and keep it as a reference. First – back to basics. The LM3915 controls ten LEDs. It controls the current through the LEDs with the use of only one resistor, and the LEDs can appear in a bar graph or single ‘dot’ when in use. The LM3915 contains a ten-stage voltage divider, each stage when reached will illuminate the matching LED (and those below it in level meter mode).

Let’s consider the most basic of examples (from page two of the data sheet) – a simple logarithmic display of voltage between 0 and 10V:

After building the circuit you can connect a signal to measure via pin 5, and the GND to pin 2. We’ve built the circuit exactly as above on some stripboard for demonstration purposes, with the only difference being the use of an 8.2kΩ resistor for R2:

To show this in action we use a signal of varying AC voltage – a sine wave at around 2 kHz. In the following video, you can see the comparison of the signal’s voltage against the LEDs being illuminated, and you will see the logarithmic voltage increase represented by the LEDs:

We used the bar display mode for the voltage increase, and the dot display mode for the voltage decrease. Did you notice that during the voltage decrease, the LEDs below the maximum level being displayed were dim? As the signal’s voltage was varying very quickly, the change in the LED’s location is a blur due to the speed of change. In the video below, we’ve slowed the frequency right down but kept the same maximum voltage.

Well that was a lot of fun, and gives you an idea of what is possible with the LM3915.

Displaying weaker signals

In non-theoretical situations your input signal won’t conveniently be between 0 and 10 V. For example the line level on audio equipment can vary between 1 and 3V peak to peak. For example, here’s a random DSO image from measuring the headphone output on my computer whilst playing some typical music:

Although it’s an AC signal we’ll treat it as DC for simplicity. So to display this random low DC voltage signal we’ll reduce the range of the display to 0~3V DC. This is done using  the same method as with the LM3914 – with maths and different resistors.

Consider the following formulae:

As you can see the LED current (Iled) is simple, however we’ll need to solve for R1 and R2 with the first formula to get our required Vref of 3V. For our example circuit I use 2.2kΩ for R2 which gives a value of 1.8kΩ for R1. However putting those values in the ILED formula gives a pretty low current for the LEDs, about 8.3 mA. Live and learn – so spend time experimenting with values so you can match the required Vref and ILED.

Nevertheless in this video below we have the Vref of 3V and some music in from the computer as a sample source of low-voltage DC. This is not a VU meter! Wait for the LM3916 article to do that.

Again due to the rapid rate of change of the voltage, there is the blue between the maximum level at the time and 0V.

Chaining multiple LM3915s

This is covered well in the data sheet, so read it for more on using two LM3915s. Plus there are some great example circuits in the data sheet, for example the 100W audio power meter on page 26 and the vibration meter (using a piezo) on page 18.

Conclusion

As always I hope you found this useful. Don’t forget to stay tuned for the final instalment about the LM3916. And if you made it this far – check out my new book “Arduino Workshop” from No Starch Press.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitter, Google+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

The post Tutorial – LM3915 Logarithmic Dot/Bar Display Driver IC appeared first on tronixstuff.

Introduction

Time for another kit review and in this instalment we have a look at the “3 digit counter” kit from Jaycar. This is part of a much larger series of kits that are described in a three volume set of educational books from Jaycar titled “Short Circuits”.

Aimed at the younger readers or anyone who has an interest in learning electronics, these books (volumes one, two and three) are well written and with some study and practice the reader will make a large variety of projects and learn quite a bit. They could be considered as a worthy 21st-century replacement to the old Dick Smith “Funway…” guides.

The purpose of this kit is to give you a device which can count upwards between zero and 999 – which can be used for various purposes and also of course to learn about digital electronics.

Assembly

The kit arrives in typical retail fashion:

Everything you need to make the counter is included except for the instructions – which are found in the “Short Circuits” volume two book – and IC sockets. Kits for beginners with should come with IC sockets.

The components are separated neatly in the bag above, and it was interesting to see the use of zero ohm resistors for the two links on the board:

The PCB is excellent. The silk screening and solder-mask is very well done.

Furthermore I was really, really impressed with the level of detail with the drilling. The designer has allowed for components with different pin spacing – for example the 100 nF capacitor and transistors as shown below:

The instructions in the book are very clear and are written in an approachable fashion:

There’s also a detailed explanation on how the circuit works, some interesting BCD to decimal notes, examples of use (slot cars!) and a neat diagram showing how to mount the kit in a box using various parts from Jaycar – so you’re not left on your own.

Construction went well, starting with the low-profile parts:

… then the semiconductors:

… then the higher-profile parts and we’re finished:

There wasn’t any difficulty at all, and the counter worked first time. Although I’m not a new user, the quality of PCB and instructions would have been a contributing factor to the success of the kit.

How it works

The input signal for the counter (in this case a button controlling current from the supply rail) is “squared-up” by an MC14093 schmitt-trigger IC, which then feeds a MC14553 BCD counter IC, which counts and then feeds the results to a 4511 BCD to 7-segment converter to drive the LED digits which are multiplexed by the MC14553. For the schematic and details please refer to the book. Operation is simple, and demonstrated in the following video:

However you can feed the counter an external signal, by simply applying it to the input section of the circuit. After a quick modification:

… it was ready to be connected to a function generator. In the following video we send pulses with a varying frequency up to 2 kHz:

Conclusion

This is a neat kit, works well and with the accompanying book makes a good explanation of a popular digital electronics subject. There aren’t many good “electronics for beginners” books on the market any more, howevert the “Short Circuits” range from Jaycar really fit the bill.

So if you’re looking to learn more about electronics or start someone else off, head in to Jaycar and have a look. Readers from outside Australia are also covered. Full-sized images are available on flickr.

And while you’re here – are you interested in Arduino? Check out my new book “Arduino Workshop” from No Starch Press.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitter, Google+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

[Note – kit and book purchased without notifying the supplier]

The post Kit Review – Jaycar “Short Circuits” 3 Digit Counter appeared first on tronixstuff.

There is an Indiegogo campaign to sell a kit for learning electronics that seems to have better pricing than most of the similar kits I’ve seen: BE MAKER! KIT plus FREE lessons on electronics, from Zero to Internet of Things | Indiegogo.

The most popular product they are selling seems to be a $69 kit with a microprocessor board (a clone of the Arduino Leonardo); a “shield” with an LCD display driver, pushbuttons, microSD card reader, 2 servo connections, RGB LED strip driver, and Ethernet adapter; a bunch of useful electronics parts (including an LCD display for the shield and an RGB LED strip); “lessons” (which are probably just assembly instructions for different projects, but may be more tutorial) and a box to keep all the tiny parts in.

As Arduino and Arduino-compatible kits go, this one looks pretty good.  Forget about it for holiday gift-giving though, as they don’t expect to deliver until February 2014.  If you want something similar for this year, look at the somewhat more expensive kits from AdaFruit or SparkFun.

There is an Indiegogo campaign to sell a kit for learning electronics that seems to have better pricing than most of the similar kits I’ve seen: BE MAKER! KIT plus FREE lessons on electronics, from Zero to Internet of Things | Indiegogo.

The most popular product they are selling seems to be a $69 kit with a microprocessor board (a clone of the Arduino Leonardo); a “shield” with an LCD display driver, pushbuttons, microSD card reader, 2 servo connections, RGB LED strip driver, and Ethernet adapter; a bunch of useful electronics parts (including an LCD display for the shield and an RGB LED strip); “lessons” (which are probably just assembly instructions for different projects, but may be more tutorial) and a box to keep all the tiny parts in.

As Arduino and Arduino-compatible kits go, this one looks pretty good.  Forget about it for holiday gift-giving though, as they don’t expect to deliver until February 2014.  If you want something similar for this year, look at the somewhat more expensive kits from AdaFruit or SparkFun.

Introduction

In this review of an older kit we examine the aptly-named “Mini Stereo Amplifier” from Dick Smith Electronics (catalogue number K5008), based on the article published in the October 1992 issue of Silicon Chip magazine.

The purpose of the kit is to offer a stereo 1W+1W RMS amplifier for use with portable audio devices that only used headphones, such as the typical portable tape players or newly available portable CD players. I feel old just writing that. At the time it would have been quite a useful kit, paired with some inexpensive speakers the end user would have a neat and portable sound solution. So let’s get started.

Assembly

Larger kits like this one that couldn’t be retailed on hanger cards shipped in corrugated cardboard boxes that were glued shut. They looked good but as soon as a sneaky customer tore one open “to have a look” it was ruined and hard to sell:

The amplifier kit was from the time when DSE still cared about kits, so you received the sixteen page “Guide to Kit Construction” plus the kit instructions, nasty red disclaimer sheet, feedback card, plus all the required components and the obligatory coil of solder that was usually rubbish:

However the completeness of the kit is outstanding, everything is included for completion including an enclosure and handy front panel sticker:

… all the sockets, plenty of jumper wire and even the rubber feet:

The PCB is from the old-school of design – without any silk-screening or solder mask:

However the instructions are quite clear so you can figure out the component placement easily. Which brings us to that point – all the components went in with ease:

… then it was a matter of wiring in the sockets, volume potentiometer and power switch:

Instead of using a 3.5mm phono socket for power input, I used a 9V battery snap instead. The amplifier can run on voltages down to 1.8V so it will do for the limited use I have in mind for the amplifier. However in the excitement of assembly I forgot the power switch:

However it wasn’t any effort to rectify that. You will also notice three links on the PCB, which I fitted instead of making coils (more on this later). So at that point the soldering work is finished:

Now to drill out the holes on the faceplate. Instead of tapering out the slots on the side of the housing, I just drilled all the holes on the front panel:

Turns out the adhesive on the front panel sticker had lost its mojo, so I might head off and get some white-on-black tape for the label maker. However in the meanwhile we have one finished mini stereo amplifier, which reminds me of an old grade seven electronics project:

How it works

The amplifier is based on the STMicro TDA2822M (data sheet .pdf) dual low-voltage amplifier IC. In fact the circuit is a slight modification of the stereo example in the data sheet. As mentioned earlier, the benefit of this IC is that it can operate on voltates down to 1.8V, however to reach the maximum power output of 1W per channel into 8Ω loads you need a 9V supply. The output will drop to around 300 mW at 6V.

Finally the Silicon Chip design calls for a triplet of coils, one each on the stereo input wires – used to prevent the RF signal being “shunted away” from the amplifier inputs. The idea behind that was some portable radios used the headphones as an antenna, however we’ll use it with the audio out from a mobile phone so it was easier to skip hand-winding the coils and just put links in the PCB.

Using the Amplifier

The purpose of this kit was to have some sound while working in the garage, so I’ve fitted a pair of cheap 1W 8Ω speakers each to a length of wire and a 3.5mm plug as shown in the image above. And for that purpose, it works very well. In hindsight it turns out the speakers were rated at 1W peak not RMS, however they still sound great.

Conclusion

Another kit review over. This is a genuinely useful kit and a real shame you can’t buy one today. And again – to those who have been asking me privately, no I don’t have a secret line to some underground warehouse of old kits – just keep an eye out on ebay as they pop up now and again. Full-sized images and much more information about the kit are available on flickr.

And while you’re here – are you interested in Arduino? Check out my new book “Arduino Workshop” from No Starch Press.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitter, Google+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

The post Old Kit Review – Silicon Chip Mini Stereo Amplifier appeared first on tronixstuff.

Introduction

In this review we examine the three digit counter module kit from Altronics. The purpose of this kit is to allow you to … count things. You feed it a pulse, which it counts on the rising edge of the signal. You can have it count up or down, and each kit includes three digits.

You can add more digits, in groups of three with a maximum of thirty digits. Plus it’s based on simple digital electronics (no microcontrollers here) so there’s some learning afoot as well. Designed by Graham Cattley the kit was first described in the now-defunct (thanks Graham) January 1998 issue of Electronics Australia magazine.

Assembly

The kit arrives in the typical retail fashion:

And includes the magazine article reprint along with Altronics’ “electronics reference sheet” which covers many useful topics such as resistor colour codes, various formulae, PCB track widths, pinouts and more. There is also a small addendum which uses two extra (and included) diodes for input protection on the clock signal:

The counter is ideally designed to be mounted inside an enclosure of your own choosing, so everything required to build a working counter is included however that’s it:

No IC sockets, however I decided to live dangerously and not use them – the ICs are common and easily found. The PCBs have a good solder mask and silk screen:

With four PCBs (one each for a digit control and one for the displays) the best way to start was to get the common parts out of the way and fitted, such as the current-limiting resistors, links, ICs, capacitors and the display module. The supplied current-limiting resistors are for use with a 9V DC supply, however details for other values are provided in the instructions:

At this point you put one of the control boards aside, and then start fitting the other two to the display board. This involves holding the two at ninety degrees then soldering the PCB pads to the SIL pins on the back of the display board. Starting with the control board for the hundreds digit first:

… at this stage you can power the board for a quick test:

… then fit the other control board for the tens digit and repeat:

Now it’s time to work with the third control board. This one looks after the one’s column and also a few features of the board. Several functions such as display blanking, latch (freeze the display while still counting) and gate (start or stop counting) can be controlled and require resistors fitted to this board which are detailed in the instructions.

Finally, several lengths of wire (included) are soldered to this board so that they can run through the other two to carry signals such as 5V, GND, latch, reset, gate and so on:

These wires can then be pulled through and soldered to the matching pads once the last board has been soldered to the display board:

 You also need to run separate wires between the carry-out and clock-in pins between the digit control boards (the curved ones between the PCBs):

For real-life use you also need some robust connections for the power, clock, reset lines, etc., however for demonstration use I just used alligator clips. Once completed a quick power-up showed the LEDs all working:

How it works

Each digit is driven by a common IC pairing – the  4029 (data sheet) is a presettable up/down counter with a BCD (binary-coded decimal) output which feeds a 4511 (data sheet) that converts the BCD signal into outputs for a 7-segment LED display. You can count at any readable speed, and I threw a 2 kHz square-wave at the counter and it didn’t miss a beat. By default the units count upwards, however by setting one pin on the board LOW you can count downwards.

Operation

Using the counters is a simple matter of connecting power, the signal to count and deciding upon display blanking and the direction of counting. Here’s a quick video of counting up, and here it is counting back down.

Conclusion

This is a neat kit that can be used to count pulses from almost anything. Although some care needs to be taken when soldering, this isn’t anything that cannot be overcome without a little patience and diligence. So if you need to count something, get one ore more of these kits from Altronics. Full-sized images are available on flickr. And while you’re here – are you interested in Arduino? Check out my new book “Arduino Workshop” from No Starch Press – also shortly available from Altronics.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitter, Google+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

The post Kit Review – Altronics 3 Digit Counter Module appeared first on tronixstuff.